Hi all, im new here and im new to converting and decoding so i have one question...

I was wondering which is better for mp3 320 CBR, Stereo or Joint Stereo?

Im using foobar 2000 v1.1.10 and LAME 3.99.3 (stable release) for converting .flac or .waw to mp3 320 cbr, mostly i download a remastered flac discographys from rock and metal bands and convert them into mp3 320.

Also i like to ask for a explanation of a few options in foobar2000?

- Encoder: i use mp3 320 CBR, than i go to custom, choose lame for encoder and there is one more option... Bit Depht Control, in Format is: it haves option lossy and option losseless (or hybrid)... which one to choose? Highest BPS mode suported i have to default, on 24.

also i like to ask for explanation for these options in Processing circled in red?

Stereo and joint-stereo are mathematically equivalent. We call joint-stereo "lossless" only to indicate this relationship and hence ease fear. It does not mean that one is lossy and the other is lossless.

QUOTE (AlexanderMKD @ Jan 19 2012, 19:03)

why Force Stereo and not just Stereo whats the difference?

The other option is forced joint-stereo, not forced stereo. This forces all frames to be mid-side, while regular joint-stereo can use either mid-side frames or left-right frames, depending on which is more efficient.

This post has been edited by greynol: Jan 20 2012, 18:42

Reason for edit: Added quotations to indicate that I'm answering two separate questions that are actually unrelated.

I am not an expert, but the custom dialog form is clearly the same for ALL encoders. It assumes you do have a bit of knowledge as to the process. You are converting to mp3; a lossy format. Choose lossy.

The Lossy or Lossless option in the foobar encoding frontend is only there to trigger the warning dialog box in foobar when doing lossy-to-lossy conversions. "Highest BPS Mode" is the maximum bit depth the encoder will take as input, which for LAME is 24-bit.

All the "Processing" options should be fairly self-explanatory. Nothing in that menu should be activated unless you are trying to change the way your audio sounds. ReplayGain applied in that menu changes the volume of the audio itself, as is explained in the gray text. The better, non-destructive way to apply ReplayGain is rather in the "Other" section of the converter menu, the checkbox called "Scan files for ReplayGain after conversion".

The better, non-destructive way to apply ReplayGain is rather in the "Other" section of the converter menu, the checkbox called "Scan files for ReplayGain after conversion".

It is clearly a matter of personal preference.

There are benefits in using any of the three general approaches: apply gain to the source data as part of the encoding process, alter gain in the lossy files after encoding, or tag and use a RG compatible player.

Myself, I go with the first option in album mode. From there I can scan in track mode and use an RG compatible player to enable track mode when desired (or convert RG to soundcheck in order to have the ability to perform the same function in the Apple ecosystem). I would not be so bold as to assume this is better than some other way.

I don't totally agree. The stereo signal can be equivalently described by the left/right resp. mid/side signal, but the quality of the corresponding encoding processes can be different.Joint stereo is targeting at achieving the best efficiency out of the two representations. In CBR mode efficiency corresponds to quality.

halb27, joint-stereo MS (mid-side) IS equivalent to stereo. You probably mean joint-stereo IS (intensity stereo), used with very low bitrates... that implementation isn't equivalent to stereo, but MS is.

No I don't. You only consider signal representation, not the encoding process.One point is that the side info of the mid/side representation has another meaning to our hearing system than the left/right/mid info which directly carry musical information. That should have its counterpart in the psy model.I don't know whether current Lame's implementation uses another psy model for the side info. In case it doesn't M/S representation should be used only when it is very safe to do so - I guess this is the way joint stereo is actually used. In case it does use a different psy model for the side info it's clear that there's a difference.

Or, put it the other way around, if the overall procedure for treating the left/right resp. mid/side representation was equivalent, there would be no decision making problem for the encoder which representation to use in a specific situation. At least not qualitywise. But that's wrong. Otherwise there wouldn't have been a change in favor of a higher amount of L/R frames.

Isn't Joint-Stereo, in the case of LAME, just an algorithm that decides if the more-efficient M-S coding can be used instead of regular L-R so as to save bits? And that the encoder will only switch to M-S if the signal for that frame is highly symmetrical with respect to the L and R channels?

Yes, that's the way joint-stereo is targeting at achieving the best efficiency out of the two representations, and, exactly as you describe, Lame 3.99's joint stereo mode switches to M/S representation only if the side info has a rather low significance.

If you enable this, and if the file being converted has ReplayGain tags (tags which say how to change the volume to make it be at a particular perceived loudness), then the info in those tags will be used to permanently change the actual volume level of the audio before it is written to the output file.

Advanced Limiter - I don't think there's any documentation for it, so I can only make an educated guess as to what it does. This is kind of an emergency dynamic range compressor. If the volume goes above a certain level that would cause clipping, then the limiter "squashes" it back down so there's no distortion. You normally don't need it unless you anticipate the other active DSPs will boost the volume too much.

Convert mono to stereo - If the original file is mono (one channel of audio), this will make it be as if it were dual-channel mono (left and right channels identical). It doesn't make the mono sound "spread" into the stereo field. So audibly it's exactly the same as single-channel. It might be useful for a situation like where you have a mono mp3 and you want to convert it to a stereo WAV for burning onto CD.

Crossfader - If converting more than one file, you can make the end of each song overlap the beginning of the next, kind of like a DJ mix, but not beatmatched.

Downmix channels to mono - If the original file is not mono (one channel of audio), then this will merge all the channels so the output file is mono. Perhaps useful if you have mono content with stereo background noise, or slightly off-center mono content in a stereo file; it will probably compress better if it's converted to true mono first, and may even sound better (or not).

Hard -6dB limiter - A more aggressive dynamic range compressor. Anything louder than a certain level gets made quieter. The net effect is that the overall volume is reduced, and quiet sounds are not so quiet anymore. It can be useful to smooth out speech or make music seem "loud" (after turning the volume back up) but at the expense of "punch".

Move stereo to rear channels - If the output format is multichannel (e.g. 5.1 or 7.1 surround), this will move the left-front channel to the left-rear, and the right-front channel to the right-rear. Why, I don't know.

Resampler (PPHS) - This is a basic resampler. If you want the decoded output file to have a different sample rate than the decoded input file, use this. Example: you have a 24-bit/96-KHz vinyl rip and you want to burn it to CD, so you need a 16-bit/44.1-Khz WAV. You can do the 96-to-44.1 part of that conversion with this DSP. The 24-to-16 part is the bit depth setting in the output format part of the converter.

Reverse stereo channels - Swaps left and right. Useful if they're wrong in the input, obviously.

Skip silence - Allows silence, or very quiet parts of the audio, to not be included in the output file. Probably useful if the input file has a lot of unnecessary silence in it?

No it's not. In joint stereo, a signal with a very high correlation between the two channels (e.g. near mono) will have a very high correlation between the coding noise added to the two channels.

In discrete stereo mode, the same near mono signal will have coding noise with a much lower correlation between the two channels added.

You shouldn't be able to hear a difference (unless you listen to the mathematical difference between the two channels, and compare the respective results), but the two are not the same at all.

Using mp3 at 320kbps CBR possibly means you don't trust the psychoacoustic model (otherwise you'd probably use a high VBR setting and benefit from lower bitrates without loss of quality). A similar naive argument ("I don't trust it") could be made for avoiding joint stereo. Of course forcing discrete stereo actually lowers the quality for near-mono signals, so it's better to trust lame's higher conservative (especially at high bitrates) joint stereo model.

The counter argument is that, if you need to switch to M/S to encode an essentially mono signal transparently (i.e. 320kbps for one channel!) then you're ****** because most of the time you only have 160kbs on average per channel (320kbps split between two channels). So forcing discrete stereo at 320kbps can't really hurt anything that badly. Whereas, in theory, using joint stereo could hurt something if that model went wrong, and (certainly at lower bitrates) audily trashes the "difference"/"side" channel - which you might listen to for karaoke.

In conclusion, at 320kbps, you can make arguments either way. If you can find more than a small handful of samples from the entire world's audio recordings where you can hear a difference, you're doing well.

Beware in relying on the results of old listening tests and reports of old problem samples. Lame has become very conservative in its use of Joint Stereo over the years.

The most challenging test sample (if you want to test the difference) is a near-mono signal, fed through a vocal-cut filter after the mp3 decoder. mp3 encoding doesn't assume the use of a vocal cut filter (or any filter) afterwards. If you never intend to do this in real life, it's not a relevant test.

You are using 320 CBR mode because your car stereo cannot play VBR? You can skip the DSPs. They are not for encoding to MP3 but for processing and changing the audio before encoding. You can do many things with that. For example equalizing your speakers and room to correct some errors. Or changing the characteristics of the audio to fit your personal style.

First I suggest to encode without DSPs. After listening some time, you can decide it there is anything that might sound better. Iīm sure people can suggest a DSP for most of your possible wishes. For example, in cars I like an exciter, a compressor to conter the noise around, some equalizer to correct the speaker system and the room, and I move the bass to the middle of the stereo field. But thatīs just me. I guess, most people dont change the sound before playing it.

QUOTE (2Bdecided @ Jan 20 2012, 18:33)

The most challenging test sample (if you want to test the difference) is a near-mono signal, fed through a vocal-cut filter after the mp3 decoder. mp3 encoding doesn't assume the use of a vocal cut filter (or any filter) afterwards. If you never intend to do this in real life, it's not a relevant test.

Is a vocal cut filter splitting the L/R-audio to M/S, removing M, and joining S back to LR? Yes, thatīs an easy way to listen to typical MP3-errors. Would you say that the possible disadvantage of M/S-encoding is an academic one and in nearly any real-live-situation M/S-encoding is the mode of choice?

Think of it this way: why would the LAME developers make joint stereo the default encoding mode if forcing L/R stereo is going to give you better results? Do you think they're deliberately trying to gimp your MP3 files? The LAME developers tweaked the psyocoacoustic model in 3.99 so that it generates more L/R frames than 3.98 does, but M/S frames are still used, because using L/R frames all the time would produce worse results. LAME is optimized to give you the best results with the default options. That's why those settings are the defaults.

What about converting an album from one FLAC file to separated FLAC for each song? Is foobar best option or there is a better software for converting to .FLAC? If it is, which compression level is the best?

As another mod/admin has merged the above post back in whilst I was moving it to the Recycle Bin, I shall just direct you to #5 of our Terms of Service, which advises against using existing threads to discuss unrelated topics.

Also, here is your answer: Neither the application nor the compression level will make any difference. Lossless is lossless is lossless is lossless is…